148 U.S. NATIONAL MUSEUM BULLETIN 233 



(1938, pp. 3-11) observed 111 nests, not one of which had been para- 

 sitized. Berger (1960, p. 118) in the same general area found 796 

 nests, of which 11 were parasitized. Three of these cases were two- 

 storied nests and two were reported in an earher paper (Berger, 

 1948, pp. 52-53). 



Conversely, Eaton (1914, p. 227) lists the goldfinch as one of the 

 common victims of the cowbird in New York, and so it seems that 

 considerable local variation must occur. In southern California the 

 goldfinch apparently is a frequent fosterer. Hanna (1928, p. 161) 

 recorded eight parasitized nests in a limited area and a limited time, 

 and M. C. Badger wi'ote me that, in his experience, the goldfinch 

 was a very common victim in southern California. 



In the absence of recent records of a cowbird being fledged from a 

 goldfinch's nest, Berger (1961, p. 271) considered it unlikely that the 

 young parasite could survive on a diet of regurgitated seeds such as 

 the goldfinch habitually gives its nestlings. Nevertheless, this phe- 

 nomenon has occurred. The earliest recorded instance, observed 

 near Baltimore, Maryland, and described by Dr. Nathaniel Potter, 

 is given in full in Alexander Wilson's pioneering work on American 

 birds (1810, p. 158). 



The records relate to three races of the goldfinch — tristis, pallidus, 

 salicamans — and to the three races of the cowbird: obscurus in 

 California; artemisiae in British Columbia, Alberta, Saskatchewan, 

 and North Dakota; and ater elsewhere. 



Lesser Goldfinch 

 Spinus psaltria (Say) 



The lesser goldfinch has been reported on a few occasions as a 

 victim of the brown-headed cowbird in California and Texas. The 

 late J. Hooper Bowles informed me many years ago that he had in 

 his collection a set of 4 eggs of this goldfinch with 1 of the cowbird, 

 taken at Santa Paula, California, by M. C. Badger. The collector 

 wrote me that he had found this bird to be an occasional victim but 

 that it was not as frequently imposed upon as its congener, S. tristis. 

 Woods (1930, p. 126) recorded another parasitized nest at Azusa. 

 A. M. Ingersoll and GriflSng Bancroft have both found similar cases 

 in San Diego County; there are three sets taken by them in the collec- 

 tion of the Western Foundation of Vertebrate Zoology and one in 

 the San Diego Museum of Natural History. In the collection of the 

 San Bernardino County Museum there is a parasitized nest of eggs 

 taken in the San Gabriel Mountains. All these Cahfornia records 

 relate to the race hesperophilus of the host and the race obscurus of 

 the parasite. 



